In the largest randomized, multicenter, double-blind trial to compare St John's Wort (hypericum perforatum) with a tricyclic antidepressant, the herb was found to be therapeutically equivalent to the drug (imipramine) in treating patients with mild to moderate depression.

Actually, the herb outperformed the drug in every clinical test used to measure depression, although the differences were not statistically significant in most cases. In addition, it was found to have a superior safety profile and caused less adverse reactions.

• A total of 324 patients at 40 different outpatient clinics in Germany were randomly assigned to treatment with either hypericum extract in tablet form or imipramine.

• St. Johns Wort was better tolerated than imipramine and fewer patients on it withdrew as a result of adverse effects. For example:

• In a 5-point scale used by participants to measure tolerability (1-excellent, 5-poor) the herb was rated on average 1.67 and the drug was rated on average 2.35.

• Adverse events occurred in 39% of patients taking St. John's Wort versus 63% of patients taking imipramine.

The study's authors conclude that Hypericum extract is as effective as imipramine, but its advantage as a first line treatment is its superior safety profile.

In a letter published on the journals web site in response to this study, Ron Law, Executive Director of the National Nutritional Foods Association of New Zealand, states "This is the 33rd randomized clinical trial reporting that the dietary supplement St John's Wort is both extremely safe and extremely effective. How much more evidence is needed ... "

He also cites a web site with a good source of information on possible interactions between St. John's Wort and various drugs.

Dr. Paul Kepkay, MD, a retired Internist, states that the study was conducted in Germany, where there are much better controls in place for herbs and physicians have more experience in their use, as compared to the US and Canada. Therefore, while not disputing the superior results of St John's Wort in the study, he maintains that these can't be transposed elsewhere.

In comments to the Optimal Wellness Center, Dr. Sam Benjamin, Medical Director of Mariposa Botanicals, states that while the quality of European products may be somewhat better, in general, due to some controls in place, there are many quality control initiatives that are being undertaken this side of the Atlantic by quality companies.

For example, according to Dr. Benjamin, quality control testing should be done by quality independent laboratories, rather than only in-house labs, which can be very biased. Some of the things which are important to test for are:

• Heavy Metals
• Microbiological Contamination
• Potency
• Insure proper raw materials are being used

"Standardization" is a concept that has both its virtues and its faults, according to Dr. Benjamin. On the plus side, it does help to get a product with consistent levels of one particular component. Unfortunately however, often the so-called "active" ingredient of a particular herb is either not known or several components may act synergistically. "The marker compounds may or may not even be the active compounds" says Victor Werbin, who is in charge of production and quality at Mariposa.

"Therefore, as much as we can at Mariposa we use 'standardization' as a way of assuring consistency, but we try as much as possible to capture the whole plant. In the future we will be identifying 4-6 components of each plant as a way of maintaining consistency. We will set up standards for acceptable variation of these components. However, we will not "concentrate" or artificially "engineer" the product to meet 'standardization'" states Dr. Benjamin.

Lastly, with all of the high-tech testing methods available, it is important not to forget about the simple methods, such as using the five senses. "I still look, taste, smell and feel these things. One look and taste can eliminate the need for testing an inferior material," says Mr. Werbin.

British Medical Journal September 2, 2000;321:566.